Safety standards: DIN VDE V 0124-100 (LV), FGW TR3 Rev. 23 (MV). ▫ Quality
standards: VDE-AR-N4105:2011-08 (LV), FGW TR3 Rev. 22 (MV). Profound ...
Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Approaches to investigate complex grid scenarios by means of novel PHIL methods’
Georg Lauss EES-Energy Department, AIT Austrian Institute of Technology, Vienna, Austria;
IEEE PES ISGT Innovative Smart Grid Technologies; October 17, 2012; Berlin; Germany;
Contents
§ § § § §
Intro Topologies of LV Grids Interfacing Algorithms for PHIL Complex Real-Time System Approach Conclusions - Outlook
Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Contents
§ § § § §
Intro Topologies of LV Grids Interfacing Algorithms for PHIL Complex real-time System Approach Conclusions - Outlook
Introduction This work is a motivated by real problems arising from industry projects and on-going cooperation with PV inverter manufacturer as well as distribution network operators (DNOs) on a national and international level. Target: Determination / enactment to integrate more renewable energy strategies from a technological, economical and not least political point of view. Various scenarios are of interest and underlie certain applicable safety and quality standards, respectively (LV, MV). § §
Safety standards: DIN VDE V 0124-100 (LV), FGW TR3 Rev. 23 (MV) Quality standards: VDE-AR-N4105:2011-08 (LV), FGW TR3 Rev. 22 (MV)
Profound knowledge and actual discussions in optimization or prototyping projects of PV inverters referred to state-of-the-art problems are adducted for an expanding range of application of possible PHIL tests .
18.10.2012
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Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Contents
Intro Topologies of LV Grids Interfacing Algorithms for PHIL Complex Real-Time System Approach Conclusions - Outlook
§ § § § §
Topologies of LV Grids D/A
Power Amplific ation
A/D
Measur ement
The implementation of PHIL tests environment enforces the use of a dedicated power amplifation units (PA).
Simulated System
Real Time Simulator
Power Interface
§ § §
R2
software
u
§
Consequences: § § §
R2 i
u’’
power inter- face(PI)
Stability considerations (Nyquist criterion) Choice of IA (accuracy, stability, …) Choice of PA (availability, use case, costs, …)
hardware
Simple test setup for a PHIL simulation – including dedicated Power interface (PI) 18.10.2012
Time delay introduced by real-time system (RTS) Dynamic behaviour of the PA Choice of interface algorithm (IA) Measurement equipment used (I/O, transducers)
hardware
i
software
Inherent ‘closed-loop originality‘ of PHIL simulation characterised by:
i
U0
U0
§
§
R1
R1
HuT
§
Power Interfaces (PIs) have to chosen according to the application in PHIL 6
Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Topologies of LV Grids Reference impedance
a
b
ZaL1
Low voltage grid topology translated into PHIL simulation system: § MIMO ITM PIs (ITM)
ZbL1
ZaL2 AC Sim ZaL3 Z1N
ZbN Inv 1
§
Inv 2
3-ph grid simulation
Grid impedances (Node a/b)
§
§
§
Neutral impedances in hardware (air coils and resistances) Line impedances in PHIL (VROPS)
PV inverters
§
§ § §
Single phase units (4kW, 230V/50Hz) PQ control method implemented: Q(U) Sourced by PV array simulators (PVAS3) in hardware
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Modelling of Components Modelling different filter designs: § Signal Filters: § § §
§
TLP ,O1 ( s ) =
K1 . K2s +1
TBP ,O 2 ( s) =
K1 s . s 2 + K 2 s + K3
AC Grid Filters: § § §
§
Used for feedback current/voltage filtering By default in the system control loop Examples: typically LP and BP filters Different Topologies used (standard literature) By default connected to PHIL simulation Examples: typ. Pi- or T section filters implemented
Power Output Filters: § § §
Output filter of the bridge (depending on topology) Get activated during simulation (relais) Examples: typ. LC or LCL filters
TLC ( s) =
K1 . K 2 s 2 LC + sLK3 + K 4
Important for stability and accuracy evaluations (Nyquist) → see Viehweider A, Lauss G, Lehfuss F. System Theoretic Aspects of Stability Determination on Linear Power Hardware-in-the-Loop Simulations. Elsevier IJEPES-S-10-00636.
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Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Modelling of Components PQ control parameter for the Q(U)method implemented:
Modelling of the different PQ control methods of PV inverters:
§
Fixed power factor (absolute, relative set-value) Cosφ(P) control Cosφ(U) control Q(U), Q(P) Dynamic control (free programmable)
§ § § § §
§
Averaging time (grid cycles): [1; 64] Reactive gradient (ΔQ / Δt) [5; 200]
Block diagram of PQ control implementation
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PQ Control Results Reference impedance
Use case: instabilities of PQ control (uncontrolled states)
a
b
ZaL1
ZbL1
ZaL2 AC Sim ZaL3
Inverter and Grid Voltage (EuT: Inv L1b, Phase L1-N / Node b) Control: Avg. Time=32 cyc., D Q/D t=200% / s
Z1N
1.15
ZbN Inv 2
Inv 1
Voltage (p.u.)
1.1
1.05
Q(U) Diagram (EuT: Inv L1b, Phase L1-N / Node b) Control: Avg. Time=32 cyc., D Q/D t=200% / s 1
ULN |UMAX| |UDB|
1
0.8 0.95
0.9
0
5
10
15 20 Inverter Active and Reactive Power
25
30
1
Active and Reactive Power (p.u.)
0.8 0.6 0.4 P Q S |QMAX|
0.2 0 -0.2
|QMAX(t)|
Reactive Power (p.u.)
0.6 0.4 0.2
Q(U) Trajectory Q(U) Characteristic UMAX [1.09 0.91]
0
UDB [1.07 0.93]
-0.2 -0.4 -0.6
-0.4
-0.8
-0.6 -0.8
-1 0.85
-1 0
5
10
15
20
25
30
0.9
0.95 1 1.05 Voltage (p.u.)
1.1
Time (s)
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Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Contents
§ § § § §
Intro Topologies of LV Grids Interfacing Algorithms for PHIL Complex Real-Time System Approach Conclusions - Outlook
Interfacing Algorithms for PHIL
SISO interface algorithms -Voltage & Current (DIA) Type §
ITM … current controlled voltage source (driven by the measured current at HuT)
§
PCD … characterized by considering an impedance that exists on the software as well as on the hardware side of the simulation
§
DIM … insertion of an additional impedance on the software side only (damping impedance)
Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Interfacing Algorithms for PHIL
Contents
§ § § § §
Intro Topologies of LV Grids Interfacing Algorithms for PHIL Complex Real-Time System Approach Conclusions - Outlook
MIMO interface algorithms -Voltage & Current Type §
ITM → robust method, easy to implement (reduced accuracy)
§
PCD → additional hardware necessary
§
DIM → equal damping impedance on soft- and hardware side; not realistic assumption
Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
System Overview Implemented Components
Modelled Components
Controller
Grid Controller
Data concentrator
Powerline-communication
Communication Simulator
Low-voltage Grid Power Grid Simulator
Simulation Message Bus (SMB)
Substation Automation Model
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UseCase – Controller in LV Grids Open Loop controller testing
Delay / packet losses (stochastic)
Grid data, measured load and generators profiles
Communication Simulator
Power Grid Simulator
Simulation Message Bus (SMB)
Substation Automation Model
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Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
UseCase – Grid Controller Grid Controller
Manual evaluation of the controller output
Simulation Message Bus (SMB)
Development and verification of grid controller
Real grid, real communication (from data concentrator) 17
System-Overview Real Components
Modelled Componenets
DataConcentrator
EGDA Client
Com Sim (+ Queue)
Powerline Communication
Grid Sim (PowerFactory) . Loads
Feeders
. Chargers
Simulation Message Bus (SMB)
Grid Control (CVCU)
Controller
Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
UseCase – (P)HIL PHIL / CHIL In-the-loop testing of the parameter setup (Q/P control) for small-scale grid-tie generators (PV inverters) Grid Controller
Powerline
Modbus
Communication Simulator
230 V
(Power) Hardware-inthe-Loop-Test Stand P/CHIL
Simulation Message Bus (SMB)
Substation Automation Model
Power Grid Simulator
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SIMTECH laboratory - concept The new AIT SimTech Laboratory offers an excellent environment for testing, verification and R&D in the field of large scale DG/RES integration, and Smart Grids applications. §
§
§
§ §
§
DR component and systems testing with highly flexible grid and primary energy source (e.g. PV) emulation Electrical interconnection, functionality and performance testing according to standards Simultaneous testing of power and communication interfaces of DR components Power-Hardware-in-the-loop (PHIL) environment Simulation and testing of single components and whole generation systems / plants Emulating smart grids scenarios
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AIT SimTech Laboratory (to be inaugurated end 2012)
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Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
SIMTECH laboratory – electrical §
Grid simulation § § § §
§
2 independent high bandwidth Grid Simulation Units: 0..480 V ; 3~, 800 kVA 3 independent laboratory grids, which can be operated in grounded/isolated mode 3-phase balanced or unbalanced operation Capabilities to perform LVRT and FRT testing
Adjustable loads for active and reactive power § §
§
§
DC Sources §
§
Freely adjustable RLC loads up to 1MW, 1MVAr (cap. and ind.) component laboratory with highly flexible grid and primary energy source (e.g. PV) emulation (LV up to 800 kVA) Parallel & serial components
5 independent dynamic PV-Array Simulators: 1500 V, 1500 A, 960 kVA
Line impedance emulation §
Adjustable line impedances for various LV network topologies: meshed, radial or ring network configuration
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SIMTECH laboratory – mechanical §
Environmental simulation § § § § §
Test chamber for performance and accelerated lifetime testing Full power operation of equipment under test inside chamber Max. footprint of equipment under test: 3,60 x 2,60 x 2,80 m LxWxH Temperature range -40㼻C..+120㼻C Humidity range: 10%..98 % r.H.
§
Power Hardware-in-the-loop (PHIL) environment § §
§
DAQ and Measurement §
§
§
General Specification § §
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Floor space: 400 m² Indoor and Outdoor test areas suitable for ISO containers
Multicore Opal-RT Real-Time Simulator P-HIL and C-HIL experiments at full power in a closed control loop
Multiple high precision Power Analyzers with high acquisition rate Simultaneous sampling of asynchronous multi-domain data input
AIT SimTech
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Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Contents
§ § § § §
Intro Topologies of LV Grids Interfacing Algorithms for PHIL Complex Real-Time System Approach Conclusions - Outlook
Conclusions §
Different components in single and three phase lv grids are under investigation; focus is on stability issues for active / reactive power control issues
§
Nowadays, not all LV topologies can be run/translated into PHIL simulation setup; complexity of MIMO systems are challenging (stability).
§
In Future, more complex lv grid scenarios should be able to be modeled and run in PHIL simulation (MIMO, advanded IA)
Q(U) Diagram (EuT: Inv L1b, Phase L1-N / Node b) Control: Avg. Time=32 cyc., D Q/D t=200% / s 1
0.8 0.6
a
b
ZaL1
Reactive Power (p.u.)
Reference impedance
ZbL1
ZaL2 AC Sim ZaL3 Z1N
ZbN Inv 1
Inv 2
0.4 0.2 0 -0.2 -0.4 -0.6 -0.8
Outlook: § More detailled investigations on PHIL test components (modeling) will be done in order to optimize simulation characteristics (stability, accuracy, BW, …) §
-1 0.85
0.9
0.95 1 1.05 Voltage (p.u.)
Comparison with real tests (lab, field) will give a better understanding and represents a verification.
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1.1
Presented at 2012 3rd IEEE PES ISGT Europe, Berlin, Germany, October 14 -17, 2012
Thank you very much for your attention!
Georg Lauss AIT Austrian Institute of Technology EES-Energy Department Vienna, Austria
[email protected]
